[TRLog] Bandmap

[KL7RA]

I would like to see a way to "clear" the bandmap with one key stroke.
Occasionally there are times when it is of some value in multi-op contesting
to "start over" with a fresh bandmap. Mults that can't be heard or bad spots
start to waste time when the maps get too large.

Also restarting TRLog brings up the last bandmap when it was shutdown.
One keystroke "clear" would help here when TRLog is in "general" mode
for DXing.

73 Rich KL7RA